Current telephone systems typically include a Ring-No-Answer timeout setting. In response to a time period or a number of rings elapsing without the telephone call being answered, an exchange re-routes the telephone call, for example to a voicemail system or another telephone number, or simply terminates the call. Some telephones also include such a Ring-No-Answer timeout setting on the telephone itself.
The Ring-No-Answer timeout setting on the telephone system, or the telephone itself, is presently only adjustable prior to a telephone call being received.